package api

import (
	"net/http"
	"testing"

	"github.com/gin-gonic/gin"

	"gitea.stevedudenhoeffer.com/steve/pansy/internal/config"
)

// agentCfg is a config with the assistant configured — a (fake) key, on, and a
// resolvable model. The key isn't real, but ValidateAgentModel/NewRunner only
// PARSE the spec (no live call), so a Runner still builds and capabilities
// reports it live. That's enough to exercise the runtime on/off swap.
func agentCfg() *config.Config {
	c := localCfg()
	c.Agent = config.AgentConfig{
		Model:             "ollama-cloud/glm-5.2:cloud",
		OllamaCloudAPIKey: "test-key",
		Enabled:           true,
	}
	return c
}

func settingsVersion(t *testing.T, r *gin.Engine, cookie *http.Cookie) int64 {
	t.Helper()
	w := doJSON(t, r, http.MethodGet, "/api/v1/settings", nil, cookie)
	if w.Code != http.StatusOK {
		t.Fatalf("get settings: status %d, body %s", w.Code, w.Body.String())
	}
	st, _ := decodeMap(t, w.Body.Bytes())["settings"].(map[string]any)
	return int64(st["version"].(float64))
}

// TestSettingsAdminOnly: the first registered user is admin and can read/write
// settings; a second user is not and gets 403 (not 404 — settings aren't a
// masked resource).
func TestSettingsAdminOnly(t *testing.T) {
	r := authEngine(t, localCfg())
	admin := registerAndCookie(t, r, "admin@example.com") // first user → admin
	member := registerAndCookie(t, r, "member@example.com")

	if w := doJSON(t, r, http.MethodGet, "/api/v1/settings", nil, admin); w.Code != http.StatusOK {
		t.Fatalf("admin GET settings: status %d, body %s", w.Code, w.Body.String())
	}

	if w := doJSON(t, r, http.MethodGet, "/api/v1/settings", nil, member); w.Code != http.StatusForbidden {
		t.Errorf("member GET settings: status %d, want 403", w.Code)
	}
	if w := doJSON(t, r, http.MethodPatch, "/api/v1/settings",
		map[string]any{"agentModel": "x", "version": 1}, member); w.Code != http.StatusForbidden {
		t.Errorf("member PATCH settings: status %d, want 403", w.Code)
	}
	// Unauthenticated is 401, before the admin check.
	if w := doJSON(t, r, http.MethodGet, "/api/v1/settings", nil, nil); w.Code != http.StatusUnauthorized {
		t.Errorf("anonymous GET settings: status %d, want 401", w.Code)
	}
}

// TestSettingsInheritFromEnv: an untouched instance reports the env model as
// effective, and an empty stored model keeps inheriting it.
func TestSettingsInheritFromEnv(t *testing.T) {
	r := authEngine(t, agentCfg())
	admin := registerAndCookie(t, r, "admin@example.com")

	w := doJSON(t, r, http.MethodGet, "/api/v1/settings", nil, admin)
	if w.Code != http.StatusOK {
		t.Fatalf("get: status %d, body %s", w.Code, w.Body.String())
	}
	body := decodeMap(t, w.Body.Bytes())
	st := body["settings"].(map[string]any)
	eff := body["effective"].(map[string]any)

	if st["agentModel"] != "" {
		t.Errorf("stored model = %v, want empty (inherit)", st["agentModel"])
	}
	if eff["model"] != "ollama-cloud/glm-5.2:cloud" {
		t.Errorf("effective model = %v, want the env value", eff["model"])
	}
	if eff["hasApiKey"] != true || eff["agentLive"] != true {
		t.Errorf("effective = %+v, want a key present and the agent live", eff)
	}
}

// TestSettingsUpdateSwapsTheRunner is the core of #79: changing settings takes
// effect on the LIVE assistant, with no restart. Driven entirely through HTTP.
func TestSettingsUpdateSwapsTheRunner(t *testing.T) {
	r := authEngine(t, agentCfg())
	admin := registerAndCookie(t, r, "admin@example.com")

	capsAgent := func() bool {
		w := doJSON(t, r, http.MethodGet, "/api/v1/capabilities", nil, admin)
		return decodeMap(t, w.Body.Bytes())["agent"] == true
	}

	// Configured and on out of the box.
	if !capsAgent() {
		t.Fatal("assistant should be live at boot with a key + enabled")
	}

	// Turn it OFF via settings → capabilities flips immediately.
	v := settingsVersion(t, r, admin)
	w := doJSON(t, r, http.MethodPatch, "/api/v1/settings",
		map[string]any{"agentModel": "", "agentEnabled": false, "version": v}, admin)
	if w.Code != http.StatusOK {
		t.Fatalf("disable: status %d, body %s", w.Code, w.Body.String())
	}
	if capsAgent() {
		t.Error("assistant still live after being disabled — the runner wasn't swapped")
	}
	// Chat now refuses, at runtime, on a route that still exists.
	gid := createGardenAPI(t, r, admin, "G")
	if w := doJSON(t, r, http.MethodPost, "/api/v1/agent/chat",
		map[string]any{"gardenId": gid, "message": "hi"}, admin); w.Code != http.StatusServiceUnavailable {
		t.Errorf("chat while disabled: status %d, want 503", w.Code)
	}

	// Turn it back ON, with an explicit model, and confirm it's live again and the
	// effective model reflects the change.
	v = settingsVersion(t, r, admin)
	w = doJSON(t, r, http.MethodPatch, "/api/v1/settings", map[string]any{
		"agentModel": "ollama-cloud/kimi-k2.6:cloud", "agentEnabled": true, "version": v,
	}, admin)
	if w.Code != http.StatusOK {
		t.Fatalf("re-enable: status %d, body %s", w.Code, w.Body.String())
	}
	if eff := decodeMap(t, w.Body.Bytes())["effective"].(map[string]any); eff["model"] != "ollama-cloud/kimi-k2.6:cloud" {
		t.Errorf("effective model = %v after change, want the new one", eff["model"])
	}
	if !capsAgent() {
		t.Error("assistant not live after being re-enabled")
	}
}

// TestSettingsRejectsBadModel: a spec that won't resolve is a 400 at save time,
// not a broken assistant on the next turn.
func TestSettingsRejectsBadModel(t *testing.T) {
	r := authEngine(t, agentCfg())
	admin := registerAndCookie(t, r, "admin@example.com")
	v := settingsVersion(t, r, admin)

	if w := doJSON(t, r, http.MethodPatch, "/api/v1/settings",
		map[string]any{"agentModel": "nonesuch/model", "version": v}, admin); w.Code != http.StatusBadRequest {
		t.Errorf("bad model: status %d, want 400", w.Code)
	}
	// agentEnabled must be a bool or null, not a string.
	if w := doJSON(t, r, http.MethodPatch, "/api/v1/settings",
		map[string]any{"agentModel": "", "agentEnabled": "yes", "version": v}, admin); w.Code != http.StatusBadRequest {
		t.Errorf("string agentEnabled: status %d, want 400", w.Code)
	}
}

// TestSettingsVersionConflict: a stale version 409s and carries the current row.
func TestSettingsVersionConflict(t *testing.T) {
	r := authEngine(t, agentCfg())
	admin := registerAndCookie(t, r, "admin@example.com")
	v := settingsVersion(t, r, admin)

	// First write succeeds and bumps the version.
	if w := doJSON(t, r, http.MethodPatch, "/api/v1/settings",
		map[string]any{"agentModel": "", "agentEnabled": false, "version": v}, admin); w.Code != http.StatusOK {
		t.Fatalf("first update: status %d, body %s", w.Code, w.Body.String())
	}
	// Reusing the old version conflicts.
	w := doJSON(t, r, http.MethodPatch, "/api/v1/settings",
		map[string]any{"agentModel": "", "agentEnabled": true, "version": v}, admin)
	if w.Code != http.StatusConflict {
		t.Fatalf("stale update: status %d, want 409", w.Code)
	}
	if cur, ok := decodeMap(t, w.Body.Bytes())["current"].(map[string]any); !ok || cur["version"].(float64) != float64(v+1) {
		t.Errorf("409 body missing the current row at the bumped version: %s", w.Body.String())
	}
}

// TestSettingsSwapUnderRace runs settings saves concurrently with chat requests,
// so `go test -race` proves the atomic swap of the live Runner is safe against
// in-flight readers. The whole point of the atomic.Pointer is this: without it,
// toggling the assistant while a request reads it is a data race.
func TestSettingsSwapUnderRace(t *testing.T) {
	r := authEngine(t, agentCfg())
	admin := registerAndCookie(t, r, "admin@example.com")

	done := make(chan struct{})
	// Readers hammer capabilities, whose h.agent.get() is the SAME atomic Load the
	// chat handler does — so this races the pointer read against the writer's swap
	// without ever invoking the model (a real Run would hit the network on a fake
	// key). If get() is race-clean here it is race-clean in chat.
	for i := 0; i < 4; i++ {
		go func() {
			for {
				select {
				case <-done:
					return
				default:
					doJSON(t, r, http.MethodGet, "/api/v1/capabilities", nil, admin)
				}
			}
		}()
	}
	// Writer: flip the assistant on and off, swapping the pointer each time.
	for i := 0; i < 12; i++ {
		v := settingsVersion(t, r, admin)
		doJSON(t, r, http.MethodPatch, "/api/v1/settings",
			map[string]any{"agentModel": "", "agentEnabled": i%2 == 0, "version": v}, admin)
	}
	close(done)
}